This invention relates to a method for controlling a display panel of an electronic programmable calculator and a personal computer.
A personal computer is generally equipped with a cathode ray tube (this is referred to as "CRT" hereinafter) so that data or a plurality of programs may be displayed at one time, while an electronic programmable calculator is generally capable of displaying no more than one line of data or program.
With a programmable calculator having a printer connected thereto, programs or data in locations as specified by the programs may be completely displayed on the printer without the need to interrupt execution of program steps. However, in the absence of a printer connected thereto, the programs or the data as specified by the programs need be displayed from line to line and execution of the programs need be interrupted during display.
Furthermore, the personal computer with a CRT is not always capable of displaying all of the program or data. In the absence of the printer connected thereto, it is preferred that execution of the program be interrupted when the program or data are displayed on the CRT in a manner similar to the programmable calculator.
In any case, which of the displays, the CRT or the printer, is employed in displaying the programs or data is determined by instructions. This leads to complexity of the instructions and it is therefore desirable that a single instruction be of use for all of the output operations and selection of which output device is to be used dependent upon whether the printer is connected.